Removing deep silt and muck deposits

ABSTRACT

A method and apparatus for removing silt, muck and other deposits from a water covered basin whose bottom has been covered with a relatively thick deposit, involving the use of a submerged housing unit supported from the surface in a controlled relationship to the deposits on the bottom of the basin. The submerged unit is provided with a gate at its forward end so as only to permit the entry of silt into the housing at the forward end as it is moved along the bottom, with the arrangement being such that a pressurized jet can be injected into the entering material to enable a workable mixture of water and silt to be achieved. Means are provided for then drawing the mixture to the surface so that the silt can be disposed of at a location outside the basin. Other facets of the invention include the use of automatic means for maintaining the submerged housing unit in a desirable relationship to the silt deposits; the use of a selectively operable gate at each end of the device so as to enable operation in either direction; and automatic means for injecting additional jets of water as needed to maintain proper consistency of the material being discharged.

United States atent Chaplin [54] REMOVING DEEP SILT AND MUCK DEPOSITS Merle P. Chaplin, 609 Drive Avenue, Winter Park, Fla. 23789 22 Filed: Oct. 16, 1970 21 Appl.No.: 82,818

[72] Inventor:

Related U.S. Application Data [63] Continuation of Ser. No. 832,125, June 11, 1969,

abandoned.

[52] U.S. Cl ..210/73, 37/59, 37/62, 61/3, 210/83, 210/96, 210/104, 210/242 [51] Int. Cl ..B0ld 21/00 [58] Field ofSearch 210/73, 96, 83,104,105,134,

Primary Examiner-John Adee Auorney.lulian C. Renfro 5 7] ABSTRACT A method and apparatus for removing silt, muck and other deposits from a water covered basin whose bottom has been covered with a relatively thick deposit, involving the use of a submerged housing unit supported from the surface in a controlled relationship to the deposits on the bottom of the basin. The submerged unit is provided with a gate at its forward end so as only to permit the entry of silt into the housing at the forward end as it is moved along the bottom, with the arrangement being such that a pressurized jet can be injected into the entering material to enable a workable mixture of water and silt to be achieved. Means are provided for then drawing the mixture to the surface so that the silt can be disposed of at a location outside the basin Other facets of the invention include the use of automatic means for maintaining the submerged housing unit in a desirable relationship to the silt deposits; the use of a selectively operable gate at each end of the device so as to enable operation in either direction; and automatic means for injecting additional jets of water as needed to maintain proper consistency of the material being discharged.

17 Claims, 14 Drawing Figures PAIENTEUMAY 2 I972 3,659,712

SHEET 2 OF 6 INIIVENTOR. MERLE P. CHAF LIN PATENTEBMAY 2 1972 SHEET 30F 6 MERLE P. CHAP N PATENTEDMM 2 I972 SHEET u BF 6 INVENTOR.

PATENTEDMAY 2 I972 SHEET 5 [1F 6 INVENTOR. MERLE P. CHAPLJN PATENTEDMM 2 1972 SHEET 8 CF 6 INVILNTO MERLE P. CHAPL\N 2i? /L,Z0/7 I Arroe.

REMOVING DEEP SILT AND MUCK DEPOSITS CROSS REFERENCE TO RELATED APPLICATION This application is a continuation of my application Serl No. 832,125, filed June 11, 1969, now abandoned:

This invention bears a relationship to my recently-issued U.S. Pat. No. 3,412,862 entitled Method and Apparatus for Cleaning Areas Overlain by a Water Body", which taught the use of an enclosed structure having an open bottom area. This structure was caused to move over the lake bottom, to bring about the agitation of the silt and adjacent bottom material, to separate the silt from the bottom material, and to remove the silt from the enclosed structure without permitting any of the agitated silt material to escape into the adjacent lake water.

The submerged structure in accordance with such patent is internally power driven, and as it travels over the lake bottom, it carries with it a floating structure on which are mounted pumps and other equipment. One of these pumps is a suction pump connected to the submerged structure by a telescoping pipe, and through which pipe the silt mixture is removed from the lake bottom.

Such an arrangement presupposes that the bottom material is sufficiently firm and stable to permit the submerged structure to travel along the bottom by means of its power driven traction wheels, while carrying with it the floating structure. There are, however, conditions where the silt or other deposit is either too thick or too unstable to provide adequate traction, and it is to provide methods and equipment for removing such type of deposit that the present invention is directed.

BACKGROUND OF THE INVENTION l. Field of the Invention This invention can be categorized with the devices and methods concerned with the cleaning of the soft bottoms of lakes and other basins of water including rivers and ponds, but most particularly with lakes in which there is little or no outflow or drainage, and which lakes have have been contaminated by silt, sludge and other ingredients washed into the lake from adjacent land areas or even from sewage disposal areas.

2. Description of the Prior art The pertinent prior art, other than my above-described patent, is believed to principally involve method and apparatus for the cleaning of filter beds, which are typically of uniform depth, and consequently not needing the automatic depth-changing apparatus taught herein. Other background patents are related to dredging apparatus, which typically does not involve apparatus designed to prevent the spread of agitated material into adjacent waters.

SUMMARY OF THE INVENTION This invention relates to the removal of deep silt and other deposits from the bottom of a basin of water such as a lake or the like, and more particularly to the use of a housing unit suspended from the surface of the water in such a close and immediate relationship to the silt deposits as to enable the effective removal of same. Gate means are provided through which the silt can enter the housing as it is caused to move along the basin. Jets of water are injected into the entering silt so as to enable a workable mixture to be achieved, with automatically operated additional jets being disposed inside the housing so that the silt-water mixture can be maintained at a desired consistency. Suction means are provided for then drawing the mixture to the surface for disposition at appropriate locations.

An operator is employed on the barge from which the submerged unit is suspended, and he may control the depth or thickness of deposit removed as.well as the direction of movement of the unit over the silt deposits. Preferably, however, sensing means are employed on the unit so that an automatic raising and lowering of the submerged unit on a moment-bymoment basis can be accomplished as may be necessary for a uniform layer of silt to be removed as the unit proceeds along the basin.

It is therefore a principal object of my invention to provide a submerged, suspended unit designed to be moved along deep muck deposits and to function to remove same uniformly and rapidly from the basin without permitting any of the material to escape into the water adjacent the unit.

It is another object of my invention to provide a bidirectional device for removing silt and other material from the bottom of a basin of water without contaminating the water of the basin with agitated material.

Yet another object of my invention is to provide an effective method of removing deep muck deposits on a uniform basis, without the danger of the apparatus used for carrying out the novel method becoming mired in the muck.

Still another object of my invention is to provide automatically functioning submerged apparatus for the effective removal of silt deposits, thus freeing the operator of the surface vessel from which the unit is suspended from certain tasks, and thus affording him more time for planning the rout to be traveled.

These and other objects, features and advantages of my invention will be more apparent from a study of the appended drawings in which:

FIG. 1 is a side elevational view of my novel apparatus, revealing a typical relationship of the floating and submerged structures;

FIG. 2 is a plan view of the device revealed in FIG. I, with certain of the portions broken away so that important structural relationships can be depicted;

FIG. 3 is a plan view of the submergible, bidirectional structure associated with my invention;

FIG. 4 is a side elevational view related to FIG. 3, with a portion of this device broken away to reveal the use of a gate to control the admission of silt;

FIG. Sis an end view taken along lines 55 in FIG. 3;

FIG. 5A is a cross sectional view taken along lines SA-SA in FIG 5 to reveal on a large scale a typical arrangement of power, fluid and support cables;

FIG. 6 is a fragmentary view showing two possible positions of the submergible structure, without the apparatus of the floating structure responsible for raising and lowering the submergible structure being revealed in some detail;

FIG. 7 is an enlarged view of a portion of the submergible device, revealing some of the relationships in greater detail;

FIG. 8 is a view somewhat resembling FIG. 7 but illustrating the manner in which jets of water are utilized for sweeping the silt through the gate and toward the entrance to the suction line attached at the top of the submerged housing;

FIG. 9 is a view to a larger scale of the large wheel or drum used on the barge in connection with the raising and the lowering of the submergible structure;

FIG. 10 is an edge view taken along the direction of the arrow 10in FIG. 9;

FIG. 11 is a cross-sectional view of the rim of the wheel taken along the lines 1 1Il in FIG. 9;

FIG. 12 is a cross-sectional view of the hub portion of the wheel taken along lines 1212 in FIG. 9; and

FIG. I3 is a showing of the use of my invention in connection with the reclaiming of a Florida lake.

Referring to FIG. 1 it will be noted that I have provided a barge 10 adapted to float upon and be propelled along the surface 12 of a comparatively shallow body of water 14. As an important facet of this invention, there is suspended below the barge a submergible silt collecting device 16 that is adapted to be supported in a desirable relationship with the deposit 18 by the use of a plurality of cables or the like. Visible in FIG. 1 is a suspension cable 48 designed to wrap around a reel or drum 49, and a cable 52 designed to wrap around a drum 53. These two drums as well as drums 51 and 55 are visible in FIG. 2, and these are operably mounted on forward portions 22 of the barge. It will be understood that by the use of four cables, located on respective drums at the four comers of the submergible device 16, the device will be suspended from the barge in a desirable relationship with respect to the deposit 18. It should be noted that there is little danger of the submerged housing becoming mired in the mud and/or silt at the bottom of the basin of water, as might tend to accur in the event the weight of the submerged housing were resting directly on a relatively soft deposit.

It is a principal goal of this invention to operate the barge in such a manner as to cause the submerged housing 16 to move along the deposit on the bottom of the lake or other body of water, and to remove such deposit in uniform layers. To that end I provide a barge with forward powerplants or engines 40 and 41, and rearward engines or powerplants 42 and 43, all of these being visible in FIG. 2. As will be appreciated, there are times that cross currents or adverse winds would tend to move the barge in such a manner as would cause the submerged housing to travel an irregular path, so I preferably construct the engines 40-43 so as to be able to rotate a full 360. This of course means that not only can I operate some or all of the engines at an angle to the centerline of the barge, but also l can effectively cause the barge to proceed either to the left or to the right as viewed in FIGS. 1 and 2.

In view of the goal of removing silt from the body of water, I provide a large hose 28, through which a layer of the deposit at a time is drawn to the surface. It will be noted that the lower end 30 of the hose is connected to the upper central portion of the housing 16, which hose then passes over the circumferential or rim portion of a large but lightweight wheel 24 that is rotatably mounted on deck portion 26 of the barge. The opposite end of the hose 28 connects at 32 to the inlet of a centrifugal pump 34, which is driven in rotation by an engine 36. This engine usually is a gasoline engine, but of course it could also be a Diesel engine or even an electric motor. As will therefore be seen, when the engine is operated, the pump 34 removes great quantities of silt mixed with water through the flexible hose 28, and expels this material through the large outlet pipe 38. As will be discussed hereinafter, this pipe 38 may be connected to a hose arranged to supply the removed silt to a location on land.

The aforementioned wheel 24 serves the purpose of preventing the hose 28 from becoming kinked when the drums or reels 49, 51, 53 and 55 are driven in rotation to raise or to lower the submerged unit 16. When the unit 16 is raised from the position shown in FIG. 1 to the position shown in full lines in FIG. 6, it is necessary for the hose 28 to be kept in an effective operating position, and to that end I have arranged for the wheel to rise as it rotates. The axle portion 44 of the wheel 24 is mounted in a pair of upstanding slotted members 71 and 72 affixed to the deck, with such axle or hub portion of the wheel 24 moving upwardly on rollers in the slots, such as in the slot 73 revealed in FIGS. 1, 9 and 12. The axle or hub portion 44 of the wheel 24 is principally supported by a pair of vertically movable members 75 and 76, with this relationship being best revealed in FIG. 10. The members 75 and 76 urge the wheel upwardly at all times, thus serving to support a. part of the weight of the submerged housing 16. The members 75 and 76 are preferably hydraulic actuators supplied with a constant but adjustable pressure. The forces associated with wheel 24 are not borne by the hose 28, but rather by a pair of cables 29 that fasten to the deck of the barge, extend around the rim of the wheel for a number of degrees, and then attach to the top of housing 16 as shown in FIG. 5.

It will of course be noted that when the housing 16 has been raised to its highest position, it tends to reside in the slotted front portion of the barge defined between the forwardly extending front portions 22. At that time the wheel 24 is disposed in its highest position, as revealed from a study of FIG. 6. To effectively guide the unit 16 in its relationships to the barge, I provide a pair of vertically-disposed tubes 67 and 68, which are slidable in guide members 69 and 70 affixed to the deck of the barge.

FIG. 2 reveals a number of ancillary features of my invention, including the operator seat 46, adjacent which is a series of controls 47 for the operation of the various devices and components associated with the apparatus. Footpedals and handlevers are also provided. Also revealed in this figure is the gear box 6! turned by the electric motor 60, which gear box in turn causes the rotation of shaft 62 that is arranged to drive the reels or drums 49 and 53 in the desired direction at any instant. The reels 49 and 51 may be mounted on a common shaft 64 driven by the shaft 62, with the shaft 65 in turn being driven by the shaft 64. The shaft 65 is responsible for driving the reel 55, with it of course being understood that the winding of the cables on the reels, and the directions of rotation of the reels are such that all four corners of the housing 16 will tend to move upwardly or downwardly together. Electricity for the motor 60 and the other electric components on the barge may be supplied from an electric generator 58, which is driven in rotation by an engine 59, such as a gasoline engine.

Also shown in FIG. 2 are the high pressure water pump 89 driven by electric motor 90, and the hydraulic pump 92, driven by electric motor 93. Tubing 91 associated with water pump 89, and tubing 94 and 95 associated with the hydraulic pump 92 cause the outputs from these pumps to be delivered to a central portion of the barge and thence they are disposed upon the outer or peripheral portion of the wheel 24, as revealed in FIGS. 5, 5A and 10. This is brought about inasmuch as hydraulic and electric power are required at the submerged unit, for purposes to be described hereinafter. Appropriate valve units 96 and 97 under the control of the operator are utilized for controlling the flow of water and hydraulic power, respectively to the submerged unit 16.

Referring to FIGS. 1, 8 and certain other figures, it is to be observed that the unit 16 is designed to be moved in either direction. For example, in FIG. I, the unit is moving to the left with the gate being open so that a layer of silt 18 can enter the unit, whereas in FIG. 8, the unit 16 is being moved to the right. In either instance, only the gate in the then forward direction is allowed to open, with the rearward gate in each instance being closed. Further, it should be noted that the actuator arrangement associated with the gates is not such as to force the gates open, but rather they allow the gates to open to whatever extent is necessary in order to let the muck enter. Because the forward gate is actually opened by the muck, it opens no further than necessary, and therefore does not allow water unmixed with muck and silt to enter.

It is important to note that the unit is designed so as to prevent agitated silt from escaping to the waters around the unit, and for that reason I provide a skirt member on each side of the unit that extends down into the silt for some distance; not skirt 17 in FIGS. 1 and 4.

It will be noted in each of the first several figures that wheel or roller members 78 and 79 are provided at the two ends of the unit 16. The member 78 is rotatably mounted on pivotallymounted frame 78a, and roller 79 is rotatably mounted on pivotally-mounted frame 790, with the structural members supporting these frames being secured to the upper portion of the unit 16 such as by welding. An electric switch 78b is associated with frame 780, and an electric switch 79b is associated with frame 79a, and it is by this arrangement that the position the rollers bear to the housing can be utilized for causing the unit 16 to be positioned vertically on a momentby-moment basis.

More specifically, whichever of the two rollers is the front roller in a given instance is caused to be associated with the vertical positioning of unit 16. For example, in FIG. I the unit 16 is of course going from right to left, with the roller 78 resting atop the muck and silt deposits 18 that are in the process of being removed by the unit 16. In contrast, the roller 79 is disposed at a lower level inasmuch as the unit 16 has already removed a layer of muck and silt say 8 inches deep. The electric switch 78b is adjusted, typically at the surface, so as to be in one electrical position when the roller 78 is below a certain angle, and in another electrical position when it is above that angle. Therefore, as the unit proceeds from right to left, the roller 78 may move vertically upwardly as well as vertically downwardly with respect to an established electrical position. If the roller tends to go up, this causes the switch to move so as to cause the electric motor 60 to be energized and to cause the unit 16 to actually be raised, whereas if the roller 78 moves downwardly, this causes this electric motor to operate so as to lower the unit to a deeper level. In this manner, this arrangement assures an accurate vertical positioning of the unit 16 on a rnoment-by-moment basis.

Whereas the roller 79 and its associated switch 79b are not involved in movement to the left, these components are responsible for the vertical positioning of the unit 16 when it is caused to move from left to right. Both switch arrangements 78]: and 7% are preferably such that a neutral position is utilized, in which position the motor 60 is allowed to remain deenergized, moving the unit 16 neither up nor down. Both switches are of course of waterproof construction.

Referring to FIGS. 1, 3, 4, 7 and 8, it will be noted that an actuator 82 is associated with gate 80, and an actuator 81 is associated with gate 83. Although electric screw jacks could be used in this instance, I prefer for these actuators to be hydraulic actuators, with a pair of lines 82a and b being utilized so that high pressure fluid can be delivered to the selected end of actuator 82, and fluid returned from the other end. Similarly, and as best revealed in FIG. 3, hydraulic lines 81a and b supply pressurized fluid to actuator 81, and allow the fluid to return from the other end. FIG. 2 shows how the lines 94 and 95 from the hydraulic pump 92, are led to the wheel 24, with FIG. 10 revealing how these and the other lines reside in appropriate grooves on the periphery of the wheel 24.

The various lines and cables extend downwardly from the wheel 24 and attach to the top of the unit 16 in the manner best illustrated in FIG. 5. FIG. 5A shows a preferred arrangement of the various lines, with the scale in this instance being large enough so that the positions of the various lines and cables can be correlated with FIG. 3. For example, it will be noted that lines 810 and 81b are at the top of FIG. 5A, thus coinciding with the placement of lines 81a and b in FIG. 3, which extend to actuator 81. Similarly, lines 820 and 82b at the bottom of FIG. 5A coincide with the placement of lines 820 and b in FIG. 3, leading to actuator 82. It should also be noted that these latter cables may be contained in the same sheath with electric leads 78c and 790, which extend to switches 78b and 7%.

FIGS. 7 and 8 reveal that the actuator 81 is connected to a bellcrank 85 rather than directly to the gate 83, and it is to be understood that a comparable arrangement is utilized in connection with gate 80. When the actuator 81 is in the contracted position illustrated in FIG. 7, the gate 83 is held by the bellcrank in the closed position, but it should be noted that when the actuator has been moved to its extended position, this does not cause the gate to open, but merely moves the bellcrank to such a position that the gate may be allowed to open. As previously mentioned, both the gates 80 and 83 are caused by the entering muck and silt to open to whatever extent necessary in order that only this material rather than relatively clear water can enter.

As illustrated in FIG. 8, a number of jets of water 86 are disposed adjacent the gate 83, with the arrangement being such that these jets serve to sweep the muck and silt into the housing as the housing is caused to move along the basin of water. As will be understood, jets 84 are disposed at the opposite end of the housing, which jets are caused to operate when the housing is being moved in the direction illustrated in FIG. 1. In other words, by the proper operation of the appropriate control or controls, the operator can cause the jets adjacent the released gate to operate, with the arrangement typically being such that the jets at the opposite end of the machine are not operating at that time.

Recourse may now be had to FIGS. 2 and 3, with FIG. 2 revealing that line 91 leading from water pump 89 branches, so that water under pressure may be delivered to manifolds 84b and 86b of FIG. 3. Fluid lines 840 and 86a of FIG. 5A coincide with the same lines in FIG. 3, with the arrangement of course being such that water in line 84a is delivered to manifold 84b, and thence sprays from nozzles 84. Similarly, water is supplied by line 86a to manifold 86b and thence to the nozzle 86. Preferably, the arrangement is such that jets 84 do not operate when jets 86 are operating, and vice versa.

Referring to FIG. 8 it will be noted that jets 87 are functioning, and although the arrangement could be such that these jets operate at all times that jets 86 function, preferably the arrangement is such that the jets 87 are selectively operable.

In FIGS. 1, 2 and 6 I revealed the use ofa density regulator 98, which is essentially a device of the type used in the paper industry so that pulp can be mixed to the desired consistency. The device 98 can be a vane type, paddle type, or electronic device, with the arrangement in each instance being such that the device reacts to the mud and silt being of too thick a consistency or viscosity. Fluid line 91a is arranged to partake of the water pressure supplied to line 91 by pump 89, and line 91a delivers this water to the device 98. Device 98 in effect functions as a valve, with the water admitted by this device then flowing into pipe or line 98a, which branches and becomes lines 87a and 88a as revealed in FIG. 5A. FIG. 3 reveals that lines 870 and 88a connect to the manifolds 87b and 88b, thus automatically supplying the nozzles 87 and 88 of these manifolds with jets of water at such time as the consistency of the mixture flowing through pipe 32 and thence through device 98 becomes too thick. The nozzles 87 and 88 are of course inactive when the entering mixture is not too thick, and it should be noted that the nozzles 87 and 88 may be arranged to be energized at the same time, or alternatively may be selectively energized so that only those nozzles nearest the gate opened at a given time will be supplied with water.

It should now be apparent that I have provided a very effective apparatus for removing silt and other deposits from a basin of water in which resides deposits of silt, muck and the like. My novel submerged unit is of course arranged to be suspended at controllable distances from the surface unit so as at all times to bear a desirable relationship to the muck and silt deposits at the bottom of the basin. Although the submerged unit can have an opening at only one end, preferably 1 utilize a bi-directional unit having a gate-controlled opening at each end with the arrangement being such that the gate at what may be regarded as the rear of the unit is maintained in a closed position, thus in conjunction with the skirts 17 to prevent an undesirable agitation of the bottom of the basin adjacent the submerged unit. As previously explained, I preferably do not bias the forward gate open, but rather utilize an arrangement by which it can be pushed open to whatever extent is necessary for the silt being encountered by the unit at any moment to be admitted.

Although the submerged unit can be controlled in depth by the operator, who is of course provided with numerous controls, I preferably utilize the described arrangement in which the sensing means associated with the then forward end of the unit is activated, which means senses the height relationship of the silt deposit residing immediately in front of the unit at any moment, and causes the operation of the suspension means on the surface unit so as to cause the relative depth of the submerged unit to change in an appropriate manner. Thus, the silt deposit will be encountered in such a relationship that the silt will enter in a relatively constant amount, such as for example 8 inches or so of silt entering on a relatively consistent basis. Although the operator can also control the jets of water being sprayed into the entering silt, I preferably utilize an automatic arrangement for controlling at least some of the jets so that a relatively consistent mixture of silt and water is drawn to the surface.

The numerous cables and hoses used to interconnect the surface unit with the submerged unit preferably extend across the rim of a large but lightweight wheel 24 which is arranged to rotate as well as to move upwardly or downwardly as the case may be, in order to prevent the hoses and lines from becoming entangled as the relationship between the surface unit and the submerged unit are caused to change. The wheel is biased in the upward direction, which bias may be brought about by the use of a pair of hydraulic actuators 75 and 76, which are caused to extend to the position shown in FIG. 6 at such time as the submerged unit has been brought into its highest position immediately adjacent the underside of the hull of the surface unit. Operation of the actuators 75 and 76 is brought about by providing appropriate hydraulic lines 75b and 76b, respectively, to these actuators, so that there is always ample pressure causing the cables 29 to be taut, thus to prevent kinking of the lines and hoses adjacent the cables. Preferably l provide a pressure equalizer 75a as shown in FIG. 9 so as to assure that virtually identical hydraulic pressure is being supplied at any given moment to the actuators 75 and 76. The amount of upward force provided by the actuators is preferably such that the submerged unit is held down by a force of say 200 pounds, thus preventing the unit from becoming mired as a result of its weight.

As should now be apparent, my contribution also includes the novel method of removing silt, muck and other deposits from a basin of water comprising the steps of moving a submerged unit suspended from the surface of the basin over the silt deposit in a controlled relation thereto, selectively opening the gates of the unit so that silt encountered by the unit can be admitted through the front gate without the bottom of the basin adjacent the unit being unduly agitated, and then drawing the silt after proper mixing with water to the surface for disposition at a remote location. The method can also include the steps of automatically controlling the height relation of the submerged unit to the silt deposit, and automatically controlling the density or viscosity of the silt-water mixture.

In FIG. 13 there is illustrated a specific use of my invention, in this instance illustrating how to reclaim the usefulness of one of Floridas lakes, namely Lake Apopka. This is a fairly large lake and is bordered on two sides and part of a third side by muck farm areas which are several feet below the normal lake level. These farms are extensively cultivated in the production of a large number of garden vegetables and similar products.

These farm areas being below the lake level frequently have an excess of water from rainfall or underground sources, and it is necessary that this excess water be disposed of, for otherwise the lands would become flooded. To do this the farm or muck lands are provided with numerous drainage ditches 108 well below the farm land level, and pumping stations such as 106 and 107 to remove the excess water from these ditches and pump it up into the lake. In doing this, unfortunately the water carries with it considerable quantities of muck or farm land material which may amount to an inch or more over the farming area each year.

This has resulted in a very severe pollution and contamination of the lake water and a heavy loss of fish life as well as severely limiting the usefulness of the lake for general water activities. The material pumped from the muck lands contains much nutrient value, which is one reason its contamination effect on the lake water has become so severe. These same nutrients recovered from the deposits now in the lake and distributed over the muck and farm lands during the off growing season would serve not only to help restore the lake to its previous status of a fishermen 's paradise, but also serve to enrich the farrn lands themselves. In other words, two valuable objectives are accomplished by this invention.

As shown in FIG. 13, the discharge pipe 38 from the surface unit can extend for substantial distances over the lake on floats or the like to a booster pump 102 disposed on the shore of the lake, with the silt and water mixture then being pumped to appropriate muck farms in the vicinity, and discharged by spray units 103 and 104. Excess water will be carried back toward the lake by the ditch and pump arrangement.

The density control of the ratio of water to silt insures that a minimum amount of water and a maximum amount of silt or muck land material is pumped back to the farm land areas.

Preferably the pipe lines delivering this material are kept as short as practicable, and the use of additional or booster pumps 102 assures that the pumped material may be kept as thick as possible. This being spread over relative large land areas during the dry season, most of the minimum of water is absorbed by the farm land and the remainder evaporates leaving the returned muck deposited on the farm land. The lake water is not recontarninated by having only a part of the agitated material removed as in common dredging operations, and there is no run off back into the lake from the material delivered to the land areas.

I claim:

1. Apparatus for removing silt and other deposits from a basin of water comprising a submerged unit, means for suspending said submerged unit at a controllable distance below a surface unit movable across the surface of the basin of water, said submerged unit having an opening through which silt and other deposits can enter said submerged unit as it is caused by the surface unit to move through the water adjacent the silt deposit, suction means for transferring the silt and other deposits ingested by said submerged unit to the surface, means for controlling the height relationship between the submerged unit and the silt deposit being encountered at any given moment and gate means on said unit and movable with respect thereto for selectively controlling said opening so that a relatively consistent amount of silt will be caused to enter said opening as said submerged unit proceeds through the basin.

2. Apparatus for removing silt and other deposits from a basin of water comprising a submerged unit, means for suspending said submerged unit at a controllable distance below a surface unit movable across the surface of the basin of water, said submerged unit having an opening through which silt and other deposits can enter said submerged unit as it is caused by the surface unit to move through the water adjacent the silt deposit, means for transferring the silt and other deposits ingested by said submerged unit to the surface, and means for controlling the height relationship between the submerged unit and the silt deposit being encountered at any given moment so that a relatively consistent amount of silt will be caused to enter said opening as said submerged unit proceeds through the basin, sensing means provided adjacent a forward part of the unit for sensing the height relationship that the silt deposit bears to the submerged unit at any given moment, said sensing means upon encountering an increased height of silt providing a signal to said height controlling means so as to bring about a commensurate upward movement of said submerged unit, and upon encountering a decreased height of silt providing a signal bringing about a commensurate downward movement of said submerged unit, thus to assure the opening of said submerged unit encountering a relatively constant height of silt deposit as it proceeds along the basin of water.

3. Apparatus for removing silt and other deposits from a basin of water comprising a submerged unit, means for suspending said submerged unit at a controllable distance below a surface unit movable across the surface of the basin of water, said submerged unit having an opening through which silt and other deposits can enter said submerged unit as it is caused by the surface unit to move through the water adjacent the silt deposit, means for transferring the silt and other deposits ingested by said submerged unit to the surface, and means for controlling the height relationship between the submerged unit and the silt deposit being encountered at any given moment so that a relatively consistent amount of silt will be caused to enter said opening as said submerged unit proceeds through the basin, said submerged unit being bidirectional, with a silt-receiving opening at both ends, gate means adjacent each of said openings, with the arrangement being such that the gate adjacent the opening regardable at a given moment as the rear opening may be maintained in a closed position, and the gate adjacent the opposite or forward opening allowed to open only to the extent necessary for the height of silt being encountered at a given moment to enter.

4. The apparatus as defined in claim 3 in which means for spraying jets of water are provided adjacent at least one of said openings, said jets of water tending to sweep the slit and other deposits into said submerged unit as it proceeds through the basin of water.

5. The apparatus as defined in claim 4 in which additional jets are provided in said submerged unit for regulating the consistency of the mixture of water with entering silt, and automatic means for turning on or off said additional jets so as to assure a relatively consistent water and silt mixture being transferred to the surface.

6. The apparatus as defined in claim 1 in which said submerged unit is a bi-directional means having opposite ends with a silt-receiving opening at both ends, said gate means being adjacent each of said openings, for controlling each of said openings, and control means provided for controlling from said surface unit, which one of said gates of said submerged unit is open at any given time.

7. The apparatus as defined in claim 2 in which said submerged unit is suspended by cables, and in which means are provided on said surface unit for preventing the tangling of the cables connected to said submerged unit.

8. Apparatus for cleaning a silt-covered water basin comprising a submerged unit suspended from a unit movable along the surface of the basin, means for automatically adjusting the depth of said submerged unit, said means including automatic control means for bringing about adjustments so that at all times said suspended unit is in a desirable relationship to the silt deposit of the basin, gate means disposed in the front of said submerged unit through which silt and other deposited material can enter the unit as it is caused to be moved along the bottom of the basin, actuator means for controlling the position of said gate means and means on said unit movable along the surface for controlling the actuator means and means by which the silt and water mixture is drawn to the surface for disposition at a remote location.

9. The apparatus as defined in claim 8 in which nozzle means are provided in said submerged unit for directing jets of water into the silt entering said submerged unit, thus to achieve a mixture of silt and water of desirable consistency.

10. Apparatus as defined in claim 8 in which means are provided on said submerged unit for indicating the direction and extent of depth adjustments of said submerged unit in order that it can be automatically maintained in a desirable relationship to the silt deposits on the bottom of the basin.

1!. Apparatus as defined in claim 8 in which said submerged unit may be moved in either direction, with openings and selectively operated gates disposed at both ends of the submerged unit, and means for operating the gates such that the gate at the rear of the submerged unit at any instant is closed, and the gate at the front of the unit is in such condition that it can be pushed open by entering silt.

12. The apparatus as defined in claim 8 in which selectively operable jets of water are provided inside said submerged unit, and automatic means are provided to control the operation of said jets based on the density of the silt-water mixture being drawn to the surface.

13. The apparatus as defined in claim 8 in which a plurality of control cables and hoses interconnect said submerged unit with the surface unit, a large wheel rotatably disposed upon the surface unit and having around its periphery a number of grooves in which said control cables and hoses can reside, said wheel normally being biased upwardly, but being arranged to move downwardly as the depth of said submerged unit is caused to increase, said wheel functioning to prevent the kinking or tangling of said cables and hoses.

14. A method for removing silt, muck and other deposits from a water covered basin whose bottom has been contaminated by deep silt deposits comprising the steps of moving a submerged unit suspended from the surface of the basin over said deposits in a controlled relationship thereto, automatically controlling the depth of said unit on a moment-by-moment basis so that at all times it is in a substantially consistent relationshi to the silt deposit of the basin, controlling the position 0 a gate at the forward portion of the umt so as to permit the entry of a relatively constant amount of silt into the housing, discharging a pressurized jet of water into the entering deposits to mix therewith so as to achieve a workable mixture of water and silt, and drawing the mixture to the surface so that silt can be disposed of at a location outside the basin, said unit functioning without disturbing or agitating the area of the basin adjacent the unit.

15. A method for utilizing a submerged, suspended unit for removing silt and other deposits from a basin of water or the like, such unit being a bi-directional unit having gate-controlled openings at both ends, comprising the steps of suspending the submerged unit from the surface of the water in a desirable relationship to the silt deposit, opening a gate in the forward portion of the unit as to permit the entry of silt while closing the rear gate, discharging a pressurized jet of fluid into the entering silt so as to achieve a desirable mixture, injecting additional jets of water into the mixture until it is of the proper consistency for traveling through a tube, and sucking the mix ture to the surface for disposition at a remote location.

16. The method as defined in claim 15 including the steps of reversing the direction of travel of said submerged unit, and changing the conditions of both gates such that the gate in what may be regarded as the forward portion of the device is always the only one open.

17. Apparatus for removing silt and other deposits from a basin of water comprising a submerged unit, means for suspending said submerged unit at a controllable distance below a surface unit movable across the surface of the basin of water, said submerged unit being generally rectangular, with suspension means connected at each of its corners, said submerged unit having an opening through which silt and other deposits can enter as said submerged unit is caused by the surface unit to move through the water adjacent the silt deposit, suction means for transferring the silt and other deposits ingested by said submerged unit to the surface, and means interacting with said suspension means for automatically controlling the height relationship between the submerged unit and the silt deposit being encountered at any given moment, so that a relatively consistent amount of silt will be caused to enter said opening as said submerged unit proceeds through the basin. 

2. Apparatus for removing silt and other deposits from a basin of water comprising a submerged unit, means for suspending said submerged unit at a controllable distance below a surface unit movable across the surface of the basin of water, said submerged unit having an opening through which silt and other deposits can enter said submerged unit as it is caused by the surface unit to move through the water adjacent the silt deposit, means for transferring the silt and other deposits ingested by said submerged unit to the surface, and means for controlling the height relationship between the submerged unit and the silt deposit being encountered at any given moment so that a relatively consistent amount of silt will be caused to enter said opening as said submerged unit proceeds through the basin, sensing means provided adjacent a forward part of the unit for sensing the height relationship that the silt deposit bears to the submerged unit at any given moment, said sensing means upon encountering an increased height of silt providing a signal to said height controlling means so as to bring about a commensurate upward movement of said submerged unit, and upon encountering a decreased height of silt providing a signal bringing about a commensurate downward movement of said submerged unit, thus to assure the opening of said submerged unit encountering a relatively constant height of silt deposit as it proceeds along the basin of water.
 3. Apparatus for removing silt and other deposits from a basin of water comprising a submerged unit, means for suspending said submerged unit at a controllable distance below a surface unit movable across the surface of the basin of water, said submerged unit having an opening through which silt and other deposits can enter said submerged unit as it is caused by the surface unit to move through the water adjacent the silt deposit, means for transferring the silt and other deposits ingested by said submerged unit to the surface, and means for controlling the height relationship between the submerged unit and the silt deposit being encountered at any given moment so that a relatively consistent amount of silt will be caused to enter said opening as said submerged unit proceeds through the basin, said submerged unit being bi-directional, with a silt-receiving opening at both ends, gate means adjacent each of said openings, with the arrangement being such that the gate adjacent the opening regardable at a given moment as the rear opening may be maintained in a closed position, and the gate adjacent the opposite or forward opening allowed to open only to the extent necessary for the height of silt being encountered at a given moment to enter.
 4. The apparatus as defined in claim 3 in which means for spraying jets of water are provided adjacent at least one of said openings, said jets of water tending to sweep the slit and other deposits into said submerged unit as it proceeds through the basin of water.
 5. The apparatus as defined in claim 4 in which additional jets are provided in said submerged unit for regulating the consistency of the mixture of water with entering silt, and automatic means for turning on or off said additional jets so as to assure a relatively consistent water and silt mixture being transferred to the surface.
 6. The apparatus as defined in claim 1 in which said submerged unit is a bi-directional means having opposite ends with a silt-receiving opening at both ends, said gate means being adjacent each of said openings, for controlling each of said openings, and control means provided for controlling from said surface unit, which one of said gates of said submerged unit is open at any given time.
 7. The apparatus as defined in claim 2 in which said submerged unit is suspended by cables, and in which means are provided on said surface unit for preventing the tangling of the cables connected to said submerged unit.
 8. Apparatus for cleaning a silt-covered water basin comprising a submerged unit suspended from a unit movable along the surface of the basin, means for automatically adjusting the depth of said submerged unit, said means including automatic control means for bringing about adjustments so that at all times said suspended unit is in a desirable relationship to the silt deposit of the basin, gate means disposed in the front of said submerged unit through which silt and other deposited material can enter the unit as it is caused to be moved along the bottom of the basin, actuator means for controlling the position of said gate means and means on said unit movable along the surface for controlling the actuator means and means by which the silt and water mixture is drawn to the surface for disposition at a remote location.
 9. The apparatus as defined in claim 8 in which nozzle means are provided in said submerged unit for directing jets of water into the silt entering said submerged unit, thus to achieve a mixture of silt and water of desirable consistency.
 10. Apparatus as defined in claim 8 in which means are provided on said submerged unit for indicating the direction and extent of depth adjustments of said submerged unit in order that it can be automatically maintained in a desirable relationship to the silt deposits on the bottom of the basin.
 11. Apparatus as defined in claim 8 in which said submerged unit may be moved in either direction, with openings and selectively operated gates disposed at both ends of the submerged unit, and means for operating the gates such that the gate at the rear of the submerged unit at any instant is closed, and the gate at the front of the unit is in such condition that it can be pushed open by entering silt.
 12. The apparatus as defined in claim 8 in which selectively operable jets of water are provided inside said submerged unit, and automatic means are provided to control the operation of said jets based on the density of the silt-water mixture being drawn to the surface.
 13. The apparatus as defined in claim 8 in which a plurality of control cables and hoses interconnect said submerged unit with the surface unit, a large wheel rotatably disposed upon the surface unit and having around its periphery a number of grooves in which said control cables and hoses can reside, said wheel normally being biased upwardly, but being arranged to move downwardly as the depth of said submerged unit is caused to increase, said wheel functioning to prevent the kinking or tangling of said cables and hoses.
 14. A method for removing silt, muck and other deposits from a water covered basin whose bottom has been contaminated by deep silt deposits comprising the steps of moving a submerged unit suspended from the surface of the basin over saiD deposits in a controlled relationship thereto, automatically controlling the depth of said unit on a moment-by-moment basis so that at all times it is in a substantially consistent relationship to the silt deposit of the basin, controlling the position of a gate at the forward portion of the unit so as to permit the entry of a relatively constant amount of silt into the housing, discharging a pressurized jet of water into the entering deposits to mix therewith so as to achieve a workable mixture of water and silt, and drawing the mixture to the surface so that silt can be disposed of at a location outside the basin, said unit functioning without disturbing or agitating the area of the basin adjacent the unit.
 15. A method for utilizing a submerged, suspended unit for removing silt and other deposits from a basin of water or the like, such unit being a bi-directional unit having gate-controlled openings at both ends, comprising the steps of suspending the submerged unit from the surface of the water in a desirable relationship to the silt deposit, opening a gate in the forward portion of the unit as to permit the entry of silt while closing the rear gate, discharging a pressurized jet of fluid into the entering silt so as to achieve a desirable mixture, injecting additional jets of water into the mixture until it is of the proper consistency for traveling through a tube, and sucking the mixture to the surface for disposition at a remote location.
 16. The method as defined in claim 15 including the steps of reversing the direction of travel of said submerged unit, and changing the conditions of both gates such that the gate in what may be regarded as the forward portion of the device is always the only one open.
 17. Apparatus for removing silt and other deposits from a basin of water comprising a submerged unit, means for suspending said submerged unit at a controllable distance below a surface unit movable across the surface of the basin of water, said submerged unit being generally rectangular, with suspension means connected at each of its corners, said submerged unit having an opening through which silt and other deposits can enter as said submerged unit is caused by the surface unit to move through the water adjacent the silt deposit, suction means for transferring the silt and other deposits ingested by said submerged unit to the surface, and means interacting with said suspension means for automatically controlling the height relationship between the submerged unit and the silt deposit being encountered at any given moment, so that a relatively consistent amount of silt will be caused to enter said opening as said submerged unit proceeds through the basin. 